>>>Hi,
>>>
>>>What works better (better practice) when creating a unique index that is used in FK constraints on child tables? Unique index using this syntax:
>>>
>>>

>>>CREATE UNIQUE INDEX IX_deptfile_cost_cent_site_no ON deptfile (cost_cent, site_no )
>>>

>>>
>>>or creating a constraint using the following syntax:
>>>
>>>

>>>ALTER TABLE [dbo].[deptfile] ADD  CONSTRAINT [IX_deptfile_cost_cent_site_no] UNIQUE NONCLUSTERED 
>>>(
>>>	[cost_cent] ASC,
>>>	[site_no] ASC
>>>)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
>>>

>>>
>>>?
>>>
>>
>>Use CREATE CONSTRAINT as when you create a unique index, the unique constraint is created anyway.
>>>TIA
>
>Just to make sure I got it. You are suggesting the following syntax?:
>
>

>CREATE CONSTRAINT IX_deptfile_cost_cent_site_no ON deptfile (cost_cent, site_no )
>

This doesn't seem correct. Your second syntax was correct.